A 1 Defining urban areas, some case studies in Finland Nordic Forum for Geostatistics Sinikka Laurila Statistics Finland
A 2 Definitions from... National Land Survey Finnish Environment Institute Technical Research Center of Finland Statistics Finland Conclusions - some issues in developing delineation
A 3 National Land Survey - in large scale maps: base map, land use map delineation based on satellite maps, built-up-areas and other available map data - in small scale maps: from scale 1: onwards delineation based on building coordinates method grid-buffer method (grid size 25mx25m) localities, when at least 180 inhabitants - no nomenclature (codes or names)
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A 6 National Land Survey... - functionality: mainly cartographic elements or delineating ”tightly” populated areas - no statistics included
A 7 Finnish Environment Institute - grid based method - data aggregated in the center of a 250m x 250m grid - preconditions: the grid contains at least 50 buildings and the aggregate area of the buildings is at least square meters - the part of water areas is added to grids - update interval 3 to 5 years
A 8 Finnish Environment Institute... - The System for Monitoring the communities - development of community indicators comparable in space and time using grid data - monitoring the inside structure and structural changes in locality areas - statistical grid data (125mx125m) from 3 km buffers of the locality centers - the system is used by 13 local offices
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A 10 Settlement Structure of the Bothnian Arc Area
A 11 Source: Finnish Environment Center, 2003
A 12 A Closer Zooming to Border Between Two Countries
A 13 Source: Finnish Environment Center, 2003
A 14 SO: Finnish datasets were adapted to Swedish coordinate system
A 15 Results: The population density of densely populated areas in Sweden is almost double compared to Finland 70 % of the population live on the 10 km wide coastal zone Source: Finnish Environment Center, 2003
A 16 Technical Research Center of Finland - based on building coordinates - building coordinates are converted to triangles - the size of the triangle page is flexible (for instance 200 m) - triangles are converted to areas, which are buffered by 50 m - grid data, point data (population, buildings, employment etc.) - a very accurate delineation
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A 18 Technical Research Center of Finland... - monitoring and describing communities and regional structures - tools provided (mainly usable in MapInfo/Vertical Mapper) : monitoring built-up areas commuting urban and rural areas traffic streames in commuting urban areas - aimed for: regional planners researchers decision making procesesses in regional planning
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A 21 and Statistics Finland
A 22 Background km 650 km Localities Built up areas Uninhabited Lakes 5.2 mil. inhabitants 1.3 mil. buildings km2 land area About 17 people per km2 Share of total land area for localities about 2.5
A 23 Requirements and bases for the delineation method Buildings The definition of localities At least 200 residents Distance between buildings max 200 meters Continuous area Do not restrict any administrative area Location x,y The use of building The number of residents
A 24 The development of the delineation method Two different methods Buffering points Gridding and buffering
A 25 Spatial parameters Different grid sizes 100 x 100 meter gridnet 100 x 100 meter grid Building point 75 x 75 meter grid 50 x 50 meter grid
A 26 Spatial parameters Different buffer Zones 100 x 100 meter grid and 50 meter buffer-zone 75 x75 meter grid and 50 meter buffer-zone 50 x 50 meter grid and 75 meter buffer-zone 100 x 100 meter gridnet Building point
A 27 The Grid- and buffer- method Clusters of buildings Buildings Two ArcInfo Grids (raster surface) Grid A, all buildings, value 50 Grid B, other than residential buildings, value 25 The final model, grid A + B, values 50 and 75 Other buildings Residential buildings
A 28 The Grid- and buffer- method The Clusters of buildings Grid to polygons Merge the polygons by 50/75 meter buffer zone
A 29 The Grid- and buffer- method The preform of localities and their “satellites” Select the areas with at least 200 residents Buffer zone with 100 meters Assemble the preform of localities and they “satellites” in one coverage
A 30 The Grid- and buffer- method The final localities Merge polygons together with 100 meters buffer zone Resize the the buffer zone back to original (-100 meters) 1057 Arpela
A 31 The Grid- and buffer- method “ By-products” “Holes” or “gaps” Built-up areas
A 32 Evaluations of the adopted method Effect to the working process Quantity of data
A 33 The evaluation of the adopted method Evaluating the results
A 34 Localities 2000
A 35 The time series: 1990,1995 and 2000 The Oulu region The density of population 812 as./km²The density of population 906 as./km²
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A 38 Conclusions - present definition provides aggregate locality statistics - unable to describe the structure or deveplopment (functionality) in localities (”urban areas”) - factors that determine urban areas besides population or buildings employment commuting municipal infrastructure supply of services...
A 39 Thank You !